1. Fields of the Invention
The present invention relates to an electromagnetic transmitter and receiver, especially to a high isolation electromagnetic transmitter and receiver that has simple structure to be applied to planar printed antennas, easy production, lower cost and compact volume to be used in various mini wireless mobile communication devices.
2. Descriptions of Related Art
In the era of information explosion, the data flow used before doesn't meet requirements of the wireless flow for communication and electronic transmission. Thus the amount of flow the wireless transmission device needs during data transmitting and receiving is increased dramatically and the antenna plays an important role in the wireless transmission device.
Nowadays a multiple-input multiple-output (MIMO) antenna is used to increase the isolation between antennas. Generally, the isolation is improved by increasing the distance between the antennas, or different polarization directions of the antennas. However, the increasing of the distance between the antennas results in that the increasing size of the antenna. As to different polarization directions of the antennas, the space require for the whole antenna needs to be changed.